If you had to choose a show to watch in Las Vegas... any show. I would have to say watch Celine Dion.
This Diva is so talented and so humble, it's like you have to see her once in your lifetime because of that voice. She's ACTUALLY singing. No lip syncing. No background music. Actual music playing and her voice singing. I am beyond impressed with her voice. She still got it.
The show itself is wonderful because she sings all her hits songs - My Heart Will Go On, Because you Loved Me, Power of Love, etc. She even sings a French song. She'll throw the audience off guard by singing a contemporary current song.
She interacts with the audience and even sings while taking selfies with some of them! It's amazing. (It pays to get front and center if you want to get a photo).
She is so humble and really talks to the audience. It isn't song, song song. She actually talks to the audience and gets emotional.
That voice is amazing and it hypnotizes you because she's singing it raw and so powerful.
Seriously, if you are going to watch a show... this should be it.